The present invention relates generally to features and devices to improve a threaded connection between two or more devices, wherein a soft interface is provided between the devices. In particular, the present invention relates to a retention feature that is configured to interfere with a threaded connection, wherein the presence of the retention feature provides increased frictional force between the threads of the threaded devices, thereby increasing the force required to disengage the devices and providing the user with tactile feedback which indicates a status of the threaded connection.
Traditional threaded conical or Luer fittings utilize a 6% Luer taper on opposing surface of the connectors to be threadedly connected. As the threads of the connectors are rotated relative to each other, the male and female conical surface are driven and wedged together, thereby forming a secure and fluid-tight connection. Most often this type of traditional connection is best accomplished when the male and female conical surfaces are either non-compliant or equally compliant, such that the opposing surfaces are able to achieve a secure fit. When tightening these surfaces, friction between the male and female conical surfaces provides resistance to disengaging the devices and further provides the user with a tactile sensation or feedback which indicates a complete and secure connection has been achieved.
With reference to FIGS. 1 and 2, a depiction of a PRIOR ART vascular access device 10 is shown. Generally, a vascular access device 10 is used to introduce a substance via a catheter 12 across the skin 14 and into a blood vessel 16 of a patient 18. The vascular access device 10 typically includes a body 20 with a lumen or opening 34 and a soft septum 22 placed within the opening. The vascular access device 10, including the body 20 and the septum 22, may comprise various structural and design modifications, as are presently known in the art.
In some examples, soft septum 22 has a slit 24 through which a separate extravascular device 26, such as a syringe, may introduce a substance into the vascular access device 10. A syringe is one exemplary separate device 26. Other suitable known extravascular devices may include additional vascular access devices, IV administration sets, a male Luer adapter, or other common or yet to be developed medical devices.
A vascular access device 10 may be combined with various other intravenous components to form a larger extravascular system 28. As part of operating the extravascular system 28, a tip 30 of the separate device 26 may be inserted into the vascular access device 10 through slit 24 of soft septum 22. The tip 30 penetrates the device 10 separating at least portions of the two opposing slit surfaces of septum 22. Septum 22 and slit 24 may be configured to seal, or at least substantially seal, around tip 30 as it is inserted into the vascular access device 10. Accordingly, the surfaces near the slit ends may not be separated until the tip 30 is sufficiently inserted into vascular access device 10. The tip 30 serves to open the slit 24 to allow fluid to pass through the device 10, into the catheter 12, and out the end 32 of the catheter when the device is in use.
Generally, the body 20 of vascular access device 10, and separate device 26 comprises a rigid or semi-rigid polymer material, such as polycarbonate or polypropylene. Septum 22 generally comprises a soft, pliable, resilient material, such as silicon or polytetrafluoroethylene. Thus, when separate device 26 is inserted through slit 24 of septum 22, septum 22 provides a soft, pliable barrier between the rigid or semi-rigid materials of separate device 26 and body 20. Although the interface between septum 22 and separate device 26 is secure and fluid-tight, the non-compliant material of separate device 26 and compliant material of septum 22 may reduce the security of the connection and reduces the desired tactile feedback to the user that is experienced with traditional Luer connections. Thus, the user may be unsure of the security of the connection which may result in the connection being over-tightened or unnecessarily examined.
In some instances, the act of threadedly coupling separate device 26 to body 20 causes an exposed portion of septum 22 to become pinched between separate device 26 and body 20. The resilient properties of septum 22 cause a “spring back” effect between the two threaded components, wherein separate device 26 may become partially unthreaded from body 20 following tightening. This “spring back” effect may further reduce the security of the connection and provide a dissatisfying tactile sensation to the user, wherein the soft interface of septum 22 prevents the user from sensing a progression of tightening between separate device 26 and body 20. The user therefore may lack confidence in the connection and may attempt to over-tighten the components, as discussed previously.
Thus, while techniques currently exist that are used for interconnecting threaded devices, challenges still exist. Accordingly, it would be an improvement in the art to augment or even replace current techniques with other techniques.